I've seen the pro-life side of the abortion debate starting to be referred to as "anti-choice", presumably by the "pro-choice" side. Without picking a side here, just realise that this will mean pro-lifers will get to call the other side "anti-life", which is the worst possible label of all four.
The reason the "pro" labels were adopted is that they summarise each side's positive arguments in a non-offensive way. When you go back to negatives such as "anti-choice", you try to silence the "undesirable" opinions in order to bolster your side against the menace of The Other Guys. It's not the way forward, and it won't settle things at all.
Mokalus of Borg
PS - It doesn't seem too common just yet.
PPS - I hope it stays that way.